During high-altitude climbs, if a climber’s limb remains in a low-temperature state for an extended period, it can lead to freezing of blood vessels and tissues, cellular dehydration, protein denaturation, inhibition of DNA synthesis, abnormal capillary permeability, and damage to capillaries. Rewarming may then cause cellular edema, aggregation of red blood cells and platelets, endothelial cell injury, thrombosis, tissue edema, increased interstitial pressure, blistering, localized ischemia, and necrosis of tissues, as well as changes in pH.
Frostbite of the extremities (such as hands, feet, ears, and nose) has long been one of the common injuries plaguing climbers and carries a relatively high risk of disability. Systemic frostbite is rare in mountaineering.
What are the symptoms of frostbite?
The affected area becomes cold, hard, and pale. Depending on severity, there may be sensations of pain, numbness, delayed response to touch, or complete loss of sensation. Upon warming, the area may turn blotchy red, swollen, and painful, or exhibit more severe symptoms such as gray-black or black discoloration. Blisters may form within 4–6 hours (or longer).
If the blisters are filled with clear fluid and are closer to the distal parts of the limbs (such as fingertips), it likely indicates only epidermal damage. If the blisters contain bloody fluid and are closer to the proximal parts of the limbs (such as the base of the fingers), it may suggest damage to the dermis and subcutaneous tissues. If the color appears gray-black or black, there is a high likelihood that the subcutaneous tissues, muscles, or bones have been damaged.
Classification of Frostbite
Medically, frostbite is classified into four degrees based on severity:
First-degree frostbite: Also known as common “frostnip,” it affects only the epidermis. The skin of the affected area becomes red, swollen, and congested, with sensations of heat, itching, and burning pain. Symptoms disappear after a few days, and healing occurs without scarring.
Second-degree frostbite: Affects the superficial layer of the dermis. In addition to redness and swelling, the affected area also develops blisters. There may be edema in deeper layers, severe pain, and dulled skin sensation. Healing occurs with scabbing.
Third-degree frostbite: Affects the subcutaneous tissues. The affected area becomes red and swollen with large blisters. The skin turns black or purplish-brown, and pain sensation is lost. Third-degree frostbite causes irreversible damage to tissues and may result in long-term hypersensitivity or pain, along with scarring.
Fourth-degree frostbite: Affects muscles and bones. When dry or wet gangrene occurs, amputation may be required.
How to prevent it?
The key to preventing frostbite is to stay warm, especially protecting the extremities.
Proper gloves: Carry gloves of varying thicknesses according to your climbing needs. They should fit well—not too tight or too loose—and you must always have spare gloves.
Proper footwear and socks: Shoes that are too tight can affect blood circulation, making you feel colder and increasing the risk of frostbite.
Proper “face protection”: Cold, windy weather can easily lead to frostbite on the ears, nose, and face. Having proper face protection can solve a lot of problems.
Insufficient warmth for the torso can make extremities more prone to frostbite.
The body tends to prioritize blood flow to more vital areas such as the brain and torso, leaving the less critical extremities “neglected.” Additionally, physical weakness and fatigue can also increase susceptibility to frostbite, and individuals may not easily notice when frostbite occurs.
When your hands or feet feel cold or even painful, keep them moving constantly.
Continuously wiggle your fingers and flex your toes—this helps maintain warmth to some extent. Feeling pain is a good sign; if you start feeling numb, it’s getting worse. If you can’t feel warmth, cold, pain, or numbness at all, that’s a serious problem and must be addressed immediately. In extreme conditions, the process from pain to numbness can happen quickly—especially with toes—so stay alert to your body’s signals.
If you’re staying in one place for a long time, keep wiggling your toes or stomping your feet.
When waiting for others or belaying during a climb, you often remain stationary in one place for long periods, which can easily lead to frostbite on your toes—especially at extremely high altitudes. For example, during the Everest summit push (at 2 AM, 8,600 meters altitude, while queuing), you need to keep wiggling your toes or stomping your feet constantly.
Finger Protection
Keeping your hands gripping an ice axe or trekking poles for extended periods can make your fingers feel very cold. Be sure to take opportunities to relax your fingers when on easier terrain. If it gets too cold, simply tuck all your fingers back into your palms, bringing them together—this way, you can still hold your tools, though with much less dexterity. Mitten-style gloves provide far better warmth than fingered gloves.
Adjust the face mask position in time
Face masks can easily cause your glasses to fog up. If you impatiently remove the face mask, you risk frostbite on your nose. Pressing your glasses against the face mask can help reduce fogging to some extent. If the face mask becomes damp from your breath and sticks to your face, it’s best to adjust its position.
If you lose your large gloves during the climb and have no spares or can’t borrow from teammates, it’s strongly recommended that you descend—even if the weather is still warm.
Bring an extra pair of socks, as high-altitude boots may get your feet wet during the climb.
Eating high-calorie foods is a great way to combat the cold.
Some Tips:
When your hands or feet feel cold or even painful, keep them moving—wiggle your fingers and flex your toes continuously. This helps maintain warmth to some degree. Feeling pain is actually a good sign; numbness is when things start to go wrong. If you can’t feel anything—no warmth, cold, pain, or numbness—that’s a serious problem, and you must address it immediately. But in extreme environments, the transition from pain to numbness can happen quickly, and you might soon forget the sensation, especially in your toes. Stay attuned to your body’s condition.
Mitten-style gloves provide far better warmth than fingered gloves.
If your face mask gets damp from your breath and sticks to your face, it’s best to adjust its position—it could freeze quickly.
Your face mask might cause your glasses to fog up, leading you to impatiently remove it, which could result in frostbitten noses. Pressing your glasses against the mask may help reduce fogging somewhat.
If you lose your large gloves during the climb and have no spares or can’t borrow any, it’s best to descend—even if the weather is still warm. Bring an extra pair of socks, as your high-altitude boots may get wet. Eating high-calorie foods is a great way to stay warm. You might also think of other effective ways to keep warm, especially your extremities.
How to Treat It?
Treating frostbite should follow these five steps: emergency evacuation from the cold environment; assessing whether to rewarm; rewarming; keeping the frostbitten area clean, dry, and warm; and medication or amputation.
Emergency Evacuation from the Cold Environment
1. After discovering frostbite, return to a warm environment (such as base camp) as quickly as possible, and then proceed to a city with medical facilities as fast as you can. The first few days of treatment are crucial—if mishandled, it could lead to amputation.
2. Protect the frostbitten area during movement: prevent further freezing and minimize external impacts to avoid additional damage to tissue cells.
3. If oxygen is available, using it may significantly help protect the frostbitten area and prevent the spread or worsening of the condition.
4. Keep the frostbitten area clean and dry. Use sterile bandages to wrap it and take antibiotics to prevent infection.
Assess Whether to Rewarm
You must isolate the area from the cold environment.
If there is a risk of refreezing after rewarming, do not rewarm.
After confirming rewarming, ensure the frostbitten area is not subjected to external force or injury.
If strenuous activities such as climbing or hiking that heavily involve the frostbitten area are still required after rewarming, then do not rewarm it.
The sooner the rewarming is done, the better. The longer the frostbite duration, the greater the damage to tissue cells.
Rewarming Treatment
The common method of rewarming is to use warm water—simply immerse the frostbitten area of the climber in water close to body temperature. The water temperature should not exceed 40°C, and should ideally be kept constant at around 38°C; soak in warm water 2–3 times a day, for 20–40 minutes each time.
The rewarming process can be very painful, so it’s advisable to prepare some painkillers. Many types of damage occur during rewarming (reperfusion injury), so caution is needed.
Clean, Dry, and Keep Warm.
After completing rewarming, if there are wounds on the frostbitten area, you can first clean them with a disinfectant to maintain cleanliness; then cover the entire frostbitten area with medication to keep it dry, and wrap it with gauze or bandages; take care to keep the frostbitten area warm to prevent refreezing.
How to Test Water Temperature
Thermometers are readily available at most pharmacies—the most accurate way to measure water temperature is with a thermometer.
If no thermometer is available, test the water temperature with a non-frostbitten part of your body; it should feel warm but not hot.
You can think of many ways to keep the water at a constant 38–39°C.
Medication and Amputation
When treating frostbite, medication primarily addresses three factors: preventing infection, restoring circulation, and promoting cell proliferation.
Infection can worsen necrotic tissue; necrotic tissue hinders local blood circulation, causing blood stasis and eventually leading to extensive tissue necrosis. Restoring circulation creates conditions for cell regeneration.
Photo courtesy of Zhou Peng
Photo courtesy of Jazz Ice
